Clutch brake assembly

ABSTRACT

A pneumatically or hydraulically operated clutch brake assembly for coupling a load to a motor is disclosed. The clutch brake assembly comprises a main body, an input shaft rotatably mounted on the main body, a drive disc mounted on the input shaft, an output shaft mounted for rotation and for a limited axial movement on the main body, a driven disc mounted on the output shaft, a first friction shoe mounted on the main body facing one face of the driven disc, a second friction shoe mounted on the driving disc facing the other face of the driven disc, spring means mounted on the main body for biasing the driven disc into engagement with the first friction shoe, and means for mounting a portion of a flexible conduit on the main body, whereby expansion of the flexible conduit portion, when pressurized fluid is present in such conduit portion, will cause movement of the driven disc from engagement with the first friction shoe into engagement with the second friction shoe, thereby coupling the motor to the output shaft.

FIELD OF THE INVENTION

This invention relates to a clutch brake assembly for coupling a motor to a load.

BACKGROUND OF THE INVENTION

It is known to provide clutch brake mechanisms for coupling an input shaft to an output shaft and for braking the output shaft when the two shafts are uncoupled. However, the known mechanisms generally use either solenoid-operated devices which must be frequently adjusted or fluid-operated cylinder and piston devices which often leak.

U.S. Pat. No. 4,271,934 date June 9, 1981, in the names of the same applicants as the present invention, discloses a brake assembly wherein use is made of the expansion of the flexible conduit connected to a driving fluid-operated motor for releasing the brake from the output shaft of the motor, when such motor is operated.

Applicants have now found that the expansion of a fluid filled flexible conduit, when the fluid is pressurized, can advantageously be used for operating a clutch brake assembly interconnecting a motor to a load.

SUMMARY OF THE INVENTION

The clutch brake assembly in accordance with the invention comprises a main body, an input shaft rotatably mounted on the main body, a drive disc mounted on the output shaft, an output shaft mounted for rotation and for a limited axial movement on the main body, a driven disc mounted on the output shaft, a first friction shoe mounted on the main body facing one face of the driven disc, a second friction shoe mounted on the driving disc facing the other face of the driven disc, spring means mounted on the main body for biasing the driven disc into engagement with the first friction disc, and means for mounting a portion of a fluid filled flexible conduit on the main body, whereby expansion of the flexible conduit portion, when the fluid is pressurized in the conduit portion, will cause movement of the driven disc from engagement with the first friction shoe into engagement with the second friction shoe, thereby coupling the input shaft to the output shaft.

A stabilizer shaft is preferably coupled to the input shaft and rotatably mounted on the output shaft for stabilizing rotation of such output shaft when coupled to the input shaft.

The main body preferably comprises a front plate, upon which the input shaft is rotatably mounted, a back plate upon which said output shaft is rotatably mounted and adapted for limited axial movement with the output shaft, a center plate secured to the front plate and means for mounting the springs between the center and back plates. The means for mounting the springs preferably include spring locaters mounted on the back plate for adjusting the tension of the springs.

The means for mounting a portion of the flexible conduit on the main body preferably comprises a front limit plate secured to the back plate and a back limit plate secured to the center plate. The flexible conduit is inserted between such two plates in such a way that expansion of the flexible conduit, when pressurized fluid is present in the flexible conduit, will separate the two limit plates and move the back plate axially to cause the driven disc to engage the friction shoe of the driving disc.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be disclosed, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a side view of a clutch brake assembly in accordance with the invention;

FIG. 2 is a section taken along line 2--2 of FIG. 1; and

FIG. 3 is a partial sectional view of the clutch brake assembly illustrated in FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 2 of the drawings, there is shown a clutch brake assembly comprising a main body including a front plate 10, a back plate 12 and a center plate 14. The center plate 14 is secured to the front plate 10 by tie rods 16 and nuts 18. An input shaft 20 is rotatably mounted on the front plate 10 by means of bearing assembly 22, having one portion secured to the front plate by means of bearing holder 24, which is itself secured to the front plate by bolts 26. The other portion of the bearing assembly is secured to the shaft by nut 18. A driving disc 30 is secured to the input shaft. Friction shoe 32 is secured to one face of the driving disc by means of bolt 34. A driving pulley 35 is mounted on shaft 20.

A stabilizer shaft 36 is mounted at one end within input shaft 20, and its other end extends within a cavity in output shaft 38 of the clutch brake assembly. Stabilizer shaft 36 is locked for rotation with input shaft 20 by means of screw 40 but, as it will be seen later, is free to move axially within input shaft 20. Stabilizer shaft 36 is rotatably mounted within output shaft 38 by means of bearing assemblies 42, each having one portion secured to the stabilizer shaft 36 by means of collar 44 and screw 46. Each bearing assembly 42 is mounted on the output shaft by means of bearing housing 48, which is itself secured to the output shaft by bolts 50. A driven disc 52 is secured to the end of output shaft 38 by means of bolts 54 screwed into collar 56, which is itself welded to the output shaft 38. Friction shoe 58 is secured to the center plate 14 by means of screws 60.

The output shaft 38 is rotatably mounted within back plate 12 by means of bearing assembly 62. The outer portion of bearing assembly 62 is secured to the back plate by bearing holder 64, which is itself secured to the back plate by bolts 65. The other portion of bearing assembly 62 is secured to the output shaft by nut 66, which is locked to the shaft by screw 68.

Springs 70, mounted on spring locater 72, are inserted between back plate 12 and center plate 14 for biasing driven disc 52 against friction shoe 58. The tension of the springs may be adjusted by means of bolts 76. As it will be noted, output shaft 38 is free to move axially with back plate 12, as it is now secured to center plate 14.

In addition, stabilizer shaft 36, which is rotatably fixed with respect to output shaft 38, is also free to move axially within input shaft 20.

A pair of front limit plates 78 are secured to back plate 12 by means of bolts 80. A pair of back limit plates 82 are also secured to center plate 14 by means of bolts 84. Front limit plates 78 have openings for the passage of bolts 84 and back limit plates 82 have similar openings for the passage of bolts 80. Openings are also provided in the back plate 12 for the free passage of the head of bolts 84. A flexible conduit 86 has an end which is plugged by a closure 87 while its other end is connected to a source of fluid such as air or oil under pressure with the interposition of a control valve to control pressurization and depressurization of conduit 86. The latter is looped through the space between the pairs of limit plates 78 and 82 and, upon expansion because the fluid is pressurized, as shown in FIG. 3, drives the back plate 12, the output shaft 38 and driven disc 52 into interengagement with friction shoe 32 of driving disc 30 to couple the input shaft 20 to the output shaft 38. When the fluid pressure is released, the flexible tube collapses, as shown in FIG. 2, and the back plate 12, the output shaft 38 and the driven disc 52 move to the left under the action of springs 70 until the driven disc 52 engages the frictions shoe 58 of center plate 14 to brake the output shaft.

The clutch brake assembly of the invention is especially advantageous when the motor driving the input shaft is an electric motor and the load must be frequently started and stopped. It permits continuous motor operation and this avoids wasting energy for starting and stopping the motor. 

What we claim is:
 1. A clutch brake assembly for coupling a load to a motor, said clutch brake assembly comprising:(a) a main body; (b) an input shaft rotatably mounted on said main body; (c) a drive disc mounted on said input shaft; (d) an output shaft mounted for rotation and for a limited axial movement on said main body; (e) a driven disc mounted on said output shaft; (f) a first friction shoe mounted on said main body facing one face of said driven disc; (g) a second friction shoe mounted on said drive disc facing the other face of said driven disc; (h) biasing means mounted on said main body for biasing said driven disc into engagement with said first friction shoe; (i) a flexible conduit containing a fluid; and (j) means for mounting a portion of said flexible conduit on said main body, whereby expansion of said flexible conduit portion, when the fluid present in said conduit portion is pressurized, will cause movement of said driven disc from engagement with said first friction shoe into engagement with said second friction shoe, thereby coupling the motor to the output shaft.
 2. A clutch brake assembly as defined in claim 1, further comprising a stabilizer shaft coupled to said input shaft and rotatably mounted on said output shaft for stabilizing rotation of said output shaft when coupled to said input shaft.
 3. A clutch brake assembly as defined in claim 1, wherein said main body comprises a front plate upon which said input shaft is rotatably mounted, a back plate upon which said output shaft is rotatably mounted and adapted for limited axial movement with said output shaft, a center plate secured to said front plate, and means for mounting said biasing means between said center and back plates.
 4. A clutch brake assembly as defined in claim 3, wherein said biasing means are spring means and said means for mounting said spring means include spring locaters mounted on said back plate for adjusting the tension of said spring means.
 5. A clutch brake assembly as defined in claim 3 or 4, wherein said means for mounting a portion of said flexible conduit on said main body comprises a front limit plate secured to said back plate, and a back limit plate secured to said center plate, and wherein said flexible conduit is inserted between said two plates in such a way that, upon expansion of said flexible conduit, when pressurized fluid is present, the flexible conduit will separate the two limit plates and move the back plate to cause the driven disc to engage the friction shoe of the driving disc.
 6. A brake for braking a load shaft comprising: a disc rotatably connected to said load shaft, a non-rotatable brake shoe mounted opposite said brake member, one of said disc member and said brake shoe being a part which is movable between a first position braking said disc, and a second position releasing said disc, a pair of non-rotatably mounted spaced plate members, at least one of which is movable and is connected to said part to move the latter between said two positions, and a conduit adapted to be connected to a source of pressurized fluid at one end and plugged at its other end, said conduit having a flexible conduit portion sandwiched between said plate members, biasing means causing relative movement of said plate members towards each other and flattening of said flexible conduit portion when no pressurized fluid is present therein, said flexible conduit portion expanding when pressurized fluid is present therein and causing relative separating movement of said plate members and consequent movement of said part from one to the other of said first and second positions.
 7. A brake as claimed on claim 1, wherein said movable plate member is connected to said part in such a way that said biasing means maintains said part in said first position and separating movement of said plate members causes said part to move from its first to its second position. 